/**
 * Created by A on 2017/2/21.
 */
(function (doc, win) {
    let docEl = doc.documentElement,
    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
    recalc = function () {
        let clientWidth = docEl.clientWidth;
        if(clientWidth<=1980){
            docEl.style.fontSize = 20 * (clientWidth / 320) + 'px';
        }else{
            docEl.style.fontSize = 20 * (414 / 375) + 'px';
        }
    };

if (!doc.addEventListener) return;
win.addEventListener(resizeEvt, recalc, false);
doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);
